Latch tripping device



April 7, 1953 H. w. SANFORD 2,634,007

LATCH TRIPPING DEVICE Filed April 7, 1947 5 sheets-sheet 1 HUGH 144 50W/0170,

MMXW

April 7, 1953 H. w. SANFORD LATCH TRIPPING DEVICE Filed April '7, 1947 5 Sheets-Sheet 2 H. w. SANFORD LATCH TRIPPING DEVICE April 7, 1953 5 sheets-sheet 5 Filed April 7. 194'? H. W. SANFORD LATCH TRIPPING DEVICE April 7, 1953 2,634,007

Filed April 7, 194'? 5 Sheets-Sheet 4 HUGH 14. .55mm/P0,

April 7, 1953 w. SANFORD 2,634,007

` LATCH TRIPPING DEVICE f Filed April 7, 1947 5 Sheets-Sheet 5 gramma/bo@ www@ spaced'farther aparttransverselyl. l l Accordingto a preferred; embodiment .on the Patented Apr. 7, 1953 .UNITED STATESV OFFICE 2,634,007 mwen 'mirrlNd-nevica Hugh Sanford, Knoxville,y Tenn., assigner .to The-.Sanford Investment: Cvmpanm.. Wilming: telg Delis ,erorspemtion of Delaware; applicati@ April 7 1947i Serial. idw-Fi;

(clean-5158i t 1 This inventionL relates-itc improvements. in latch tripping devices, of the character used for .con-

Y trolling. the-.release of dropfhottoml doors.` of ccnl veyances, such as mine: cars.,

Thisis an iniprovenient on v.the latchtripping mechanism set forth .ifn'l my priori.-patent, No. 233.991,.'208,` granted May-*'11* 19461.l AInthev prior device, the latelr`trpping`mechanisrn was operated by alu'g onV a sidefsillotthe ear,...w.hich would requirez thev lug tobedisposed laterallizfof the. latch hooi; which supportsltlie dcor,landlcauses a sorne whatmorer complex:apparatufsv tof .loe required than is desired.

They object' ofv thisf-inventionkis to'vsimplifyfand improve the constructionof theflatcntripping. d`evicey andthe mannen in whichziti's: operated. automaticafllyl by thecar.; bjr1 providingfor Athe .operation of the: tripping device-.directly opone. of! the latchedl doori This k'providesforhringingi the conf trolling means v'ery close `to .the-:point Lwlerezthe latch hook. is located, often remotesfron theside 'sills of the cai; in. closer relationshiplto the latch hook.v Fiirtherrnore, if .-the.rearsoendsillfstructn-re .should droop", for .when therwheelA treads should wear;4 causingtheilatchaliookto be lowered closer to the `tcpv of therails;l the. rear: door'- will 'bei `lowered correspondingly; and the? relationship vbetween the tripping'. means fandthef nookwillnot be changed appreciaflly-V TheV operationpf .the latch .tripping devicei directly by the.latcheddooritselfnot onlyp'rovid'es aJ fInnen.simpler` and. less; .expensnzev mechanism that :is more practicar to manufacture; loutl also makes possible the supporting'. of4 theudoor. yby .two

laterally spaced hookswlii-"cl'i` canibelironght `fairly close together on the longitudinal axis of the car,

'directly"behindl the central pomper of' the end-sill l engagingf eleinentsj on the doorabove thefrail 'would {be more I nearly the sa-ineen'. such .azhent l'door than itwouldbeif ithesea elernentst were' invention, provision is made for latchinggthedrop bottom :door ordoorsgof the-.conveyanceiby means of a latch hook which engages the; rear edge-,of

the; latcheclvdoers.- .endemica.heelsfpreferablv is disposed above'rthe lower edge of. the end sill,.as described in my patent',N'o`. 2,399,703,^ as .well as above the lovveri edge of the' door;A A tripping arm ifsmo'nted inthe trackway in position to be raised into engagement withthe latch hook int properly timed relation with the movement of the car o1' conveyance over' the tripping device; This' operation of the` tripping arinl preferably is accomplisledl loy means of a lever' arm operatively connect'ed witni'tlie tripping arm and disposed in close relation..therewithgin position to be op'erated directlvlby* thelat'chedf'dooritself, It is preferre'dthat the operation oiVA the lever arm beaccornp'lished' by' fnfieans'-A ofa depression provided inthe bottom of the" door plate.` Such a depression ordinarilyl yis"formedtnerin for engagement with; tnefdborclowsngf'ra-ils provided at the point of diini'ping, whicndepre's'sion may be used for this purpose, withont thenec'essity for additional modification of the door plate'.` The proportioning' of thefA lever arm and tripping arm may be suchj as Ato* raise the` tripping arminto position Vfor' 'engagement with the latch hook, as the car orl conveyance passesover the tripping device.

When'ftlfie; ear"wheels` wear or if theend sill structure Ishould; droop', thismay cause a loweringo'f' hCIlQIIRaI position of the door plate relative to the'` latch tripping device' mounted inthe norway. I

To accommodate forthi's change in relationship, nie; arms may' befmcunted' inI yieioabie positions in tlietrackwaynorin'ajlly toghe heldin X'ed relation, theretoibiitf `capableof yielding to abnormal pressure l exerted'` 'on 'the' `lever arm by"` the door plate'to allow the conveyance to pass, thereover, iorgproperoperationf thftripping' device. Illis :naires it :possilolevfcrfthefsame tripping. device to be. use@ beth @reep-eetsrtfioe that hai/eiwit been worn or` distorted, andfor cars inr which the operating. lparts havet been displaced soinewhat relative .to` eachother. 'The .tripping and lever armsnormally will beheldy in their operating positions, bult maybeamovedvbodily downward on the vyielda'lole.mounting. thereof to' accommodate .fory a door' thatVv has been .lowered somewhat relative-v to-` the traelwayf dnefto'wear or' other vimperfection intlie carl The Ain.rteii-01'1 '.iS'iHPStfated Certain @mbpdinentsin the accom anyng drawings fin which:

Fig. 3 is a cross section therethrough on the line 3--3 of Fig. 2;

Fig. 4 is a cross section similar to Fig. 3, but showing a central latch hook for the door;

Fig. 5 is a detail longitudinal section similar to Fig. 2, showing a further modification of the structure;

Fig. 6 is another longitudinal section similar to Fig. 2, and showing a modification; and

Fig. 7 is a cross section therethrough, on the line I-1, of Fig. 6.

This invention is shown as applied to a mine car of the general type set forth in my prior patent, No. 2,001,471, granted May 14, 1935, adapted for conveying coal or other`loose lading from a receiving point to a tipple or other point of discharge. The mine car is shown to b e of the 4-wheel type, having three drop bottom doors interconnected for release in one-two-three order. This application of theinvention is used, however, merely for purpose of illustration, and it is evident that the subject-matter of this invention may be applied to other types of cars, vehicles, and drop bottom conveyors in general, wherever it may be desirable to release bottom doors for dropping, in which the principles of this invention may be applicable.

The general structure of the car illustrated comprises a car body formed of side and end walls I and 2, rigidly secured together, the side walls I rising from a pair of oppositely disposed side sills 3 (Figs. 3 and 7), connected together at the ends of the car by means of combined end-sills and bumpers, designated generally at 4. The side and end-sills 3 and 4 comprise the frame structure of the car for supporting the lading body thereof, and between which is a bottom opening designated generally at 5 (Fig. 3) for discharge of the lading therethrough.

The car is supported upon wheels E and axles 'I connected with the side sills 3. The wheels 6 are adapted to travel on a track formed by a pair of laterally spaced rails indicated generally at R.

Each of the doors 8, 9 and I0, usually is pivotally supported or hinged at its forward edge, capai ble of downward swingingmovement at the point of discharge or tipple for discharge of the lading. Each of the forward or middle doors supports the free edge of the next forward door in the construction usually employed heretofore in the art,

while the rear edge of the rearward door is adapted to be latched, and, when released, will allow successive or simultaneous dropping of the doors, according to the character of mountings used for the doors, various forms of which are well-known and have been used in the art.

In the form of 'door supporting mechanism. shown in my prior patent, No. 2,001,471, three drop bottom doors were illustrated and adapted for discharge in one-two-three order from front to rear of the car, the pivotal mountings for the middle and rear doors permitting bodily slidable movement thereof. Then upon release of the rearward door, it may drop sufficiently to drag and move bodily rearward, thereby releasing the Y free edge of the middle door which will likewise drop and release the free edge of the forward door. This occurs usually just before the car reaches the tipple or bin, and permits dropping of the forward door in the bin forV discharge of the lading thereon, as soon as room enough is provided in the bin therebeneath. The other 'doors drop in succession during the continued ,forward movement of the car over the bin or tipplein one-two-three order from front to rear of the car.

After dumping in passing over the bin or tipple, the doors are adapted to be closed by the usual door-closing rails located in the track. The doors have downward projections or indentations I2 in the under faces thereof to ride on the door-closing rails, which indentations extend transversely of the doors throughout substantial portions of the width thereof. The doors are thus moved successively about their hinge rods to their closed positions, and the lmiddle and rearward doors are pushed forward into wedging relation with the next forward door, adapted to be latched in closed position. A

As shown in Figs. 2te "I, provision is made for latching the free edge of the rearward door I0 in closed position, thereby holding the several doors closed, to retain the lading in the car until the latching means is released for dumping. For this purpose, I have provided on the free edge of the rearward door I0, one or more supporting trunnions I4, one for each latch of said door. I prefer 'to use a pair of latches, each designated generally by the numeral I5 and spaced apart symmetrically with respect to the longitudinal center plane of the car, designated P (Fig. 3).

Each of the latches I5 is provided with a transverse engaging face IS thereon, as hereinafter described more in detail. The latches I5 are pivotally mounted on a cross shaft I'I supported by brackets or plates I8 secured to the adjacent end wall 2 of the car. Each of the latches I5 is preferably so constructed, or spring-pressed at 22, as to be disposed normally in its door-supporting position, or tor return thereto automatically when disengaged for release of the lading.

Each of the latches I5 is provided with a concave seat I9 (Fig. 2) at the forward face thereof in position tov receive the end of the adjacent rtrunnion I4 attached to the free edge of the rearward door I0. As shown in Fig. 2, the seat I9 is located on the opposite side of the vertical plane passing through the pivot axis of the latch I5 from the door I0, so that the weight of the door and the lading thereon tends to maintain the latched relation without any tendency for this weight to push the latch to one side. This is particularly .true when the concave seat is engaged by a convex end of the trunnion, whereby :any movement of the latch tending to release Y sides of the upright central plane P of the car by a single tripping device operating in engagement with either of the latches. The manual release of the latches may be accomplished by a squared portion 2I von the free end of the cross shaft I1 (Fig. 3) externally of the side wall I of the car.

Vswinging movement of the latch hook between the two positions shown in full lines and in dotted lines in Fig. 2.

The latches I5 are-interposed between the free tithe freani/ard door I and tneadiacentend riiCtnreA-underneath asuard plate 21.` te `the adjacent end. wall 2 and4 which guard plate is supported alsoon the` top edges of themeuntins plates `or bracketsv It.y ,Theiatenes I5- areso constructed and arrarlieedv that they are disposed wholly above thelower edges o f theend-sills of, thecar,` and, also, preferably, above the lower face ofthe rearward door, protected positions. This prevents disarrange ment of the latches or damage thereto inthe eventof wreckage of the Vcar or fromcontactwith obstructions in the trackway, as might occur in` a .mineg thusK assuring adequate protectionl oi the latches: to maintain these inproper operative positions. Eachlatch I5 is so mounted in protected position` betweenivthe door I-IJl andthe bumper. 4 that a tripping space. is; provided between said dooltnand the. latch I5 in `latchedposition for entry of a tripping arm; therebetween.

,'Ivhe tripping mechanism for the latches I5 is adapted for mounting in the trackway between. theopposite rails R at a point adjacent the bin onother point of dumping.

Thisptripping mechanism `may be attached toA thejrails R or supported thereby or otherwise in` the trackvvay.

In the form illustrated in Figs. 2 and 3,A the tripping mechanism is shown as mounted on a supportingplatesuch asl a. channel bar-28,*rigidly securedas by Welding toy spacers ,29, at opposite ends thereof, by means of Which the mounting plate 23 is secured rigidlyito the track rails R.

Where two latch hooks are provided spaced on opposite sides of the longitudinal upright central plane-of the car, a tripping device may beprovidedif desired, for each suchlatch hook,r or both hooks may be operated by a single tripping device. It is preferred, however, that separate `tripping devices be used. Each such` tripping device. may Ybeof the form shown in Figs. 2 and 3, which illustrateoneform of this invention.

. In this/formare illustrated bearing boxes 30, secured upon the mounting plate 28 in longitudinal l,spacer-1 relation, andjournaled therein is a mounting pin 3I;. The. bottom of each bearing boor 351s slotted at 32, to permitl vertical displace,- mentothemounting pin 3l,l relative to the journal boxesftf, This mounting pin normally is retained in its uppermost position, as shown in 2l bya b earingplate. 33,.urged upward lby meansfo'l a coiled spring 34., interposedbetween thebearingplate 33 anda socket 35, provided-in the Vmountingplate 28,. This will permit ,bodily downward-,movement of the mounting pin 3.I,- whilenormally retaining the pin in its uppermost position. i l 1 Extending` upwardly from the journalpin 3l is a lever arm 36, having a Wedge-shaped upper end-with abeveledface 31 in position; to engage thebottomfaceof the, door depression I2. This leverarm 36 normally is urged in al counterclockwise direction about the journal pin 3l, by afweightd attached thereto.

Also journaled on the pin 3l isvr al trippingarm. 39;;gwhicl1-extendssubstantially in a rearward' direction from the journal pin. As shown in Fig. 3v,

the tripping arm` 39 is. mounted in Aside-by-side relation to theflever arm 36 and is free, of direct. attachment thereto. However, the back end of the tripping arm 39 has an offset bracketilli,r overlappingq-theiback face of the` lever arm 36,- and through whiehbracket 40 isl threaded a stop screw-.A1, the rorWaroLendof which isdn; positonl tcfvb'e feng-aged' by. ^`Ifnet lever arm; :3.6. i: This causes thelerer armee be moved by the trin- Ditlg. arm,Y 35i Lfrom the full linev position..` shown in Fig. 2, to the ldotted line position therein, whenever the tripping-armis'in its lower-dotted line position,` resting upon a stop- 42.- The tripping arm 3a normally is urged into this position inengagementwithV the stop42, not only by its Weight, but also byl a coiled spring connected at one end with: thetripping arm 3.9, and adjust.- ably connected by a screw 44,` attached at its `opposite end to a bracket 485.v secured to, the mountingplate 28. The adjustment of the vtension of the spring` `43 varies the upward, movementofthe trippingy arm 39.

The lever arm 36 is also-.connected through al cable 115,y with acrank rod. 41,; journaled inthe trackway, to move the lever arm to its inoperaf tive position,v as hereinafter-described.

The forward end,- oi the tripping arm 39l has an engagingviaceV 4.9,.. in positionto engage the face I 6 of thelatch hook-I5., The-:relation of the faces It and isis such that there .is no tendency for the face- `it!!f to slip oi of. the face It until the latchhook I5 is Vretracted to its unlatched position, as show-n in dotted lines in` Fig.{2. This angle of relationship insures positive unlatching of the hook Whenever the k trip-V ping arm engages it by the movement of the conveyance over the trippingdevice.l IIfhis angular relationship is described more in detailV 1in my prior application` for.V Latch` Tripping Mechanism, SerialNo. 571,170, `pled January 3,. 19.45.

The bracketplate I8 hasa beveledlower `face to, that extends downwardly from a pointk above the ltripping position ofthe arri-1x39 to thelower edge. of the bumper-,4, invposition to engage a lateral ange 5I` (Fig. 3).- pfrovidedon one side of the tripping arm 39 at theV outer end. thereof, to insure'of` a deiiection of the. tripping armffunderneath the bumper 4 frorrrapoint above` the. lower edge of the latter.`

Thus the bracket plate1 I8 serves. a multiple function. It provides for the support of the latch `shaft Il, the deector plate 2,` and the.

compression spring 2.2, that acts on the latch hook; and it also provides-.awedging deector for the face of the lange5l.,.v that will guide the tripping armV 39. underneath. theend-.sill structure. The latter function isespecially important when the cars` are beingnumped rapidly: to as sure the loweringofzthe `tripping arm from its engagement with the latchhook without direct abutment against ,the forward face vof `the end--k to itsidottedline position inFigf. 2, in the patho the operating depression-lf2", inthe car: door. rIhe counter-Weight.38v tends to; holdthe lever` arnrSii` againsttheadjustingscreiv 4I, and in its upright position. Howeven when itis de-` siredto move the cars over the tripping mechanisms, without. release of the-doors, the lever arm` 36V` can be rockedfin a clockwise direction. on the mounting pin 3,-I,A `and held in positionI where ity will not engage; the` tripping flug I2.

Thismaybe accomplished byy the operation of the crankbar 4rljourna led inthe trackway, and.

which is connected with the lever arm 36 through` 7er the :flexiblefrcable 46;;which;;c'able should;` have suicie'nt looseness, so as not to be tight when the lever arm 36 is in the position shown in Fig. 2.

It will be evident from Fig. 3, that the depressions I2 in the bottom faces of the doors usually extend throughout the major portion of the width of the doors. Where these indentations are used to operate the latch tripping device, according to this invention, such indentations would extend over theV tripping device as indicated at I2 in Fig. 3, in the latchedndoor of the car, but would be terminated short of the upright longitudinal plane of the tripping mechanism, as indicated at I2 in the other doors of the car, such as the doors 8 and 9.

Where the car is provided with a single latch hook I5, midway of the width of the door, as shown in Fig. 4, this may be operated by a tripping device of the character described above, including a tripping arm 39, and a lever arm 36, which will function and operate substantially as described. 'Ihe lever arm 36 will be operated by the indentation I2 in the latched door, which indentation will extend continuously throughout the intermediate portion of the latched door, but for the other doors of the car, this indentation will be terminated at the center thereof, as indicated at I2 in Fig. 4.

Where the latch tripping device is used in connection with a car equipped with doors adapted to be opened in one-two-three order, and which must beemoved bodily by a forward wedging movement to a closed position, as set forth in my prior patent, No. 2,001,471, it is preferred that the bracket plate I8 should not be used as the wedging means. It is preferred that a separate or auxiliary means for this purpose be used, as shown in the form of a bracket 53 in Fig.4 5, welded to the forward face of the end-sill structure 4.

If the car door is not made precisely accurately, or if the door becomes bent in service, or the end-sill structure should droop, or the wheels become worn, the indentation that serves as the operating lug for the tripping device might be lowered below the position shown in the drawings. Provision is made to accommodate for such irregularities in the normal location of the indentation I2, relative to the lever arm 36. One form of adjustment for this purpose is shown in Figs. 2 and 3, in the yieldably mounted journal pin 3l carried by the springs 34. Thus, if too much pressure exists between the indentation I2 and the lever arm 36, the pin 3l will be lowered and the lever arm 36 will be relieved of undue pressure, allowing it to Yoperate in the usual manner.

Another manner of providing for this adjustment is shown in Figs. 6 and '7, in which the mounting plate 28 is separate from the spacers 29, and is so mounted that the plate 28 can move downwardly relative to the track rails R.

In this form,v the mounting plate 28 is retained by bolts 55, which extend downward through the spacer 29, and the corresponding end of the mounting plate 28, and through a coniining plate 56, slidably mounted thereon. Interposed between the confining plate 56 and the under side of the mounting plate 28 are compression springs 51, the tension of which may be adjusted by the bolts 55. These springs l take the undue pressure that may arise between the lever arm 36 and the indentation I2 in the latched projection 58, on one side of the tripping arm 39', in position forengagement with the end-sill structure, as a safety means for guiding the tripping arm therebeneath when no other guiding means is provided. This may be important, particularly, when the cars are operated at an unduly high speed.

Otherwise, the device shown in Figs. 6 and '7 operates in the same manner as the tripping device, described above, in connection with Figs. 2 and 3.

Also as shown in Fig. 3, auxiliary rails are shown at R', underneath the lateral edges of the doors to prevent the doors from coming into contact with the tripping device, except for operation. 'Ihese rails R are placed in the track beside the tripping device, so that the door, when unlatched and falling, will not strike the tripping mechanism in its normal position. Furthermore, these rails R will protect the tripping mechanism from being struck by mine cars which may be derailed at the dumping bin.

While the invention has been illustrated and described in certain embodiments, it is recognized that variations and changes may be made therein, without departing from the invention, except as specied in the claims.

I claim:

1. In conveying mechanism, the combination with a trackway, a dumping vehicle mounted on the trackway and including a frame structure, a drop bottom dumping door, and latch means for holding the door closed and movable to release the same for dropping, of latch tripping mechanism mounted in the trackway, said tripping mechanism comprising a tripping member normally out of the path of movement of the vehicle and being constructed for upward movement into the path of the latch means to release the same, an actuating member operatively connected withV the tripping member in position to be engaged by the dumping door during movement of the vehicle thereover for actuating the tripping member to raise the same to said release position, said actuating member being free of the tripping member for movement to an inoperative position relative thereto, and means connected with the actuating member normally tending to move said member to said operating position.

` 2. In conveying mechanism, the combination with a trackway, a dumping vehicle mounted on the trackway and including a frame structure, a drop bottom dumping door, and latch means for holdingthe door closed and movable to release the same for dropping, of latch tripping mechanism mounted in the trackway, said tripping mechanism comprising a tripping member normally out of the path of movement of the vehicle and being constructed for upward movement into the path of the latch means to release the same, an actuating member operatively connected with theV tripping member in position to be engaged by the dumping door` during movement of the vehicle thereover for actuating the tripping member to raise the same to said release position, said actuating member being free of the tripping member for movement to an inoperative position relative thereto, means connected With the actuating member normally tending to move said member to said operating position, and yieldable means normally tending to move the tripping member to its normal position out of the path of movement of the vehicle.

- 3. In conveying mechanism, the combination with a trackway; adumping vehicle mounted on 'the trackwayand intluding alframestructure, a

lber to raise the same to said `release position,

pivot means supportingsaidV tripping and actuating members, and means yieldably mounting the pivotmeans for bodily yielding movement of the tripping and actuating members uponA the application to the actuating member of excess pressure exerted bythe door..

4. In conveying'rnechanism, the combination withra trackway, a dumping vehicle mounted on i the, trackway and. including a frame structure, a

drop bottom dumping door, and latch means for holding the door closed and movable to release the same for dropping, of latch tripping mechanism mounted in the trackway, said tripping mechanism comprising a tripping member normally out of the path of movement of the vehicle and being constructed for upward movement into the path of the latch means to release the same, an actuating member operatively connected with the tripping member in position to be engaged by the dumping door during movement of the vehicle thereover for actuating the tripping member to raise the same to said release position, a shaft supporting the tripping and actuating members, and spring mean yieldably supporting the shaft for bodily displacement of the shaft in response to excess pressure applied to the actuating member by engagement of the door therewith.

5. In conveying mechanism, the combination i with a trackway, a dumping vehicle mounted on the trackway, said Vehicle including a frame structure with transverse end portions, a drop bottom dumping door, and latch means for holding the door closed and movable to release the same for dropping, said latch means being located wholly above the lower edge of the transverse end portion of the vehicle in the same longitudinal upright plane, of latch tripping mechanism mounted in the trackway and including a tripping member normally out of the path of lmovement of the latch means and being mounted for upward movement into the path of the latch means to release the same, an actuating member operatively connected with the tripping member,

ymeans connected with the door in position to engage the actuating member as the` vehicle passes thereon to raise the tripping member to said release position, and means forming a wedging surface on the transverse end portion of the vehicle, and the tripping member having a portion thereof in the upright longitudinal plane of said wedging surface during movement of the vehicle over the tripping mechanism in position to be engaged thereby for forcing the tripping member down out of said release position after actuation of the latch means.

6. A latch tripping device adapted to control the release of a drop bottom door of a dumping conveyance, comprising a tripping member adapted to engage and release latch means, an actuating member operatively connected with the tripping member and adapted toA be actuatedk by a portion of the conveyance passi-ng thereovel, a shaft mounting the tripping and actuating members thereon, a` supportingbearing having an upright slot therein within which the. shaft is slidably mounted for upwardmovementand spring meansv bearing upon the shaft and urgingthe shaft, upwardly in the vslot for bodily yielding movement in response to excessivepressure applied to the actuating member upon engagement thereof by the, conveyance.

'.7. In conveying, mechanism, the combination with a: trackway, a dumping vehicle mounted on the trackway and including a drop bottomdoor, latchmeans, for holding the door closed and movable to release.v the same for dropping, said door having a downward .projection thereon intermediate the width thereof, ofa latch tripping mechanism mounted in the trackway including a tripping arm normally out'y of the path of the vehicle, said tripping arm beine mounted i. for upward movement into the path of the latch, means to release the same, and aneetuating: member operatively connected with the tripping arm1 and substantially in the same upright longitudinal plane as the latch means and in the path of the door projection for engagement thereby as the vehicle passes over the tripping mechanism for actuating the tripping arm to raise the same to said release position.

8. In conveying mechanism, the combination with a trackway, a dumping conveyance mounted on the trackway and including a frame structure having transverse end portions, and a drop bottom door, latch means for holding the door closed and movable to release the same for dropping, said latch means having an actuating portion thereof above the lower edge of the transverse end portions of the frame structure, said door having a downward projection thereon intermediate the width thereof between opposite sides of the frame structure, of latch tripping mechanism mounted in the trackway and including a tripping member normally out of the path of the e conveyance, means mounting said tripping member for upward movement into operative engagement with the actuating portion of the latch means above the lower edge of the transverse end portions of the frame structure, and an actuating member connected with the tripping member and substantially in the same upright longitudinal plane as the latch means and in the path of the door projection for engagement thereby as the vehicle passes over the tripping mechanism for actuating the tripping member to raise the same to said engaging position.

9. In conveying mechanism, the combination with a trackway, a dumping vehicle mounted on the trackway and including side sill structures and a transverse end structure and a drop bottom door, latch means for holding the door closed and movable to release said door for dropping, means mounting the latch means on the transverse end structure spaced inwardly from the side sill structure, said door having a downward projection thereon intermediate the width thereof, of a latch tripping mechanism mounted in the trackway and including a tripping member normally out of the path of the vehicle, said tripping member being mounted for upward movement into the path of the latch means to release the same, and an actuating member operatively connected with the tripping member and substantially in the same upright longitudinal plane as the latch means and in the path of the door projection for engagement thereby as the vehicle passes over the tripping mechanism for actuating the tripping member to raise the same to said release position.

10. In conveying mechanism, the combination with a trackway, a dumping vehicle mounted on the trackway and including side sill structures and a transverse end structure and a drop bottom door, a pair of latch members for holding the door closed and movable to release said door for dropping, means pivotally mounting the latch members on the transverse end structureA with said latch members spaced apart and spaced inwardly appreciably from the side sill structures, each of said latch members having an actuating portion thereon, said door having a downward projection on the bottom thereof intermediate the width of the door, of a latch tripping mechanism mounted in the trackway and including tripping members normally out of the path of the vehicle, each of said tripping members being pivoted for upward swinging movement into the path of the actuating portion of one of the latch members to release the latter, and an actuating member operatively connected with each tripping member and substantially in the same up- 12 right longitudinal plane as one of the latch members and in the path of the door projection for engagement thereby as the vehicle passes over the tripping mechanism for actuating the tripping members to raise the same to release engagement with the latch members.

HUGH W. SANFORD.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Number Name Date 703,257 Hatton June 24, 1902 1,195,975 Carmichael Aug. 29, 1916 2,225,462 Rose Dec. 17, 1940 2,362,986 Cate et al. Nov. 21, 1944 2,399,708 Sanford May 7, 1946 2,487,447 Kepner Nov. 8, 1949 FOREIGN PATENTS Number Country Date 1,966 'Great Britain Apr. 24, 1913 of 1913 

